Fix: OpenSSL 3.x reports unexpected EOF as SSL error

src/openssl.cr

@@ -88,20 +88,35 @@ module OpenSSL
           message = "Raised erroneously"
         when .syscall?
           @code, message = fetch_error_details
-          if @code == 0
+          {% if LibSSL.has_constant?(:SSL_R_UNEXPECTED_EOF_WHILE_READING) %}
+            if @code == 0
+              # FIXME: this isn't a per the OpenSSL documentation for how to
+              #        detect EOF, but this fixes the EOF detection spec...
+              message = "Unexpected EOF while reading"
+              @underlying_eof = true
+            else
+              cause = RuntimeError.from_errno(func || "OpenSSL")
+            end
+          {% else %}
             case return_code
             when 0
-              message = "Unexpected EOF"
+              message = "Unexpected EOF while reading"
               @underlying_eof = true
             when -1
               cause = RuntimeError.from_errno(func || "OpenSSL")
               message = "I/O error"
             else
               message = "Unknown error"
             end
-          end
+          {% end %}
         when .ssl?
-          @code, message = fetch_error_details
+          code, message = fetch_error_details
+          @code = code
+          {% if LibSSL.has_constant?(:SSL_R_UNEXPECTED_EOF_WHILE_READING) %}
+            if get_reason(code) == LibSSL::SSL_R_UNEXPECTED_EOF_WHILE_READING
+              @underlying_eof = true
+            end
+          {% end %}
         else
           message = @error.to_s
         end

src/openssl/error.cr

@@ -21,5 +21,17 @@ module OpenSSL
       message = String.new(LibCrypto.err_error_string(code, nil)) unless code == 0
       {code, message || "Unknown or no error"}
     end
+
+    protected def get_reason(code)
+      {% if LibCrypto.has_constant?(:ERR_REASON_MASK) %}
+        if (code & LibCrypto::ERR_SYSTEM_FLAG) != 0
+          (code & LibCrypto::ERR_SYSTEM_MASK).to_i
+        else
+          (code & LibCrypto::ERR_REASON_MASK).to_i
+        end
+      {% else %}
+        (code & 0xFFF).to_i
+      {% end %}
+    end
   end
 end

src/openssl/lib_crypto.cr

@@ -268,6 +268,12 @@ lib LibCrypto
   fun err_get_error = ERR_get_error : ULong
   fun err_error_string = ERR_error_string(e : ULong, buf : Char*) : Char*
 
+  {% if compare_versions(OPENSSL_VERSION, "3.0.0") >= 0 %}
+    ERR_SYSTEM_FLAG = Int32::MAX.to_u32 + 1
+    ERR_SYSTEM_MASK = Int32::MAX.to_u32
+    ERR_REASON_MASK = 0x7FFFFF
+  {% end %}
+
   struct MD5Context
     a : UInt
     b : UInt

src/openssl/lib_ssl.cr

@@ -284,6 +284,11 @@ lib LibSSL
     fun ssl_ctx_set_security_level = SSL_CTX_set_security_level(ctx : SSLContext, level : Int) : Void
     fun ssl_ctx_get_security_level = SSL_CTX_get_security_level(ctx : SSLContext) : Int
   {% end %}
+
+  # SSL reason codes
+  {% if compare_versions(OPENSSL_VERSION, "3.0.0") >= 0 %}
+    SSL_R_UNEXPECTED_EOF_WHILE_READING = 294
+  {% end %}
 end
 
 {% unless compare_versions(LibSSL::OPENSSL_VERSION, "1.1.0") >= 0 %}